The invention relates to a spatula for sampling which comprises an elongated stem having a flat scraper at least at one end of the stem.
The spatula according to the invention has been invented particularly for biological sampling i.e. collection of cells and secretion (mucus) for example in the region of ectocervix, for examination of the taken cell sample. However, the invention is not limited to a spatula for this special type of sampling; the spatula can also be used for other kinds of sampling e.g. from the oral cavity, the throat, or other mucous membranes.
A spatula for sampling from the ectocervix is shown and described in GB-B-1 429 689. In the embodiment described therein the scraper forms three lobes one lobe thereof projecting axially from one end of the stem, the other two projecting each at one side of the axial lobe transversely of the stem. The other end of the stem forms a handle for the manipulation of the spatula at sampling from the ectocervix. Then, the central lobe is introduced into the external os, and the spatula is rotated at least one turn, cells and secretion being scraped from the uterine cervix and the endocervical canal in the region of the external os where cellular changes by experience appear initially at developing cancer. The cellular sample can be transferred from the spatula to a slide by the sample being smeared directly onto the slide, being fixed and stained in order then to be examined in a microscope (so called Papanicolau test or Pap smear), or the spatula can instead be immersed into a transport solution wherein the cellular sample is washed off the spatula in order then to be transported with the transport solution to a laboratory where the cellular sample by means of different preparation techniques is transferred to a slide for manual or computer controlled examination in a microscope. It is of course important at such sampling that the cellular sample is retained on the spatula up to the smearing or washing, respectively, which has been observed in U.S. Pat. No. 3,592,186 which relates to an instrument for collecting cells for cytological examination, said instrument comprising a stem having a scraper at one end and a handle at the other end. The scraper being substantially heart-shaped with two projecting lobes, a longer one and a shorter one, the axes of which are perpendicular to each other. In this document it is recommended that the inherently hydrophobic surface of the scraper presents a rough structure. This can be achieved by a suitable treatment of the surface, but there are also materials which inherently have a suitable surface structure, e.g. some kinds of wood. Wooden spatulas are, however, not suitable for sampling for two reasons: firstly, it is difficult to smear the cellular sample onto a slide because the wooden spatula is too stiff, and, secondly, the cellular material will be sucked into the wooden spatula which has a hydrophilic surface so that the taken cellular sample partly adheres to the spatula. As a consequence thereof a smaller amount of cellular material will be deposited onto the slide.
GB-B-1 429 689 mentions nothing regarding the surface structure of the spatula described therein, which is made of plastic, but in practice spatulas of plastic material for scraping off cellular samples generally have been made with a matted or frosted surface in order to improve the adhesion of the cellular sample to the spatula.
However, it has been found that not even such a surface structure of the scraper provides a satisfactory adhesion. The adhesion perhaps could be improved by increasing the roughness of the matted or frosted surface but this may involve difficulties in smearing the taken cellular sample onto a slide.
EP-B-0 050 632 shows and describes an instrument for sampling from the ectocervix, which in its entirety is injection molded of clear polypropylene and includes an aspirator for sampling by aspirating secretion (mucus) from the endocervical canal, as well as scrapers for collecting cells from the ectocervix. A substantially linear axial through aspiration bore opens at about the centre of the tip of a scraper. In EP-B-0 050 632 the manner in which the sampling is made is illustrated in detail.
DE-C2-37 90 193 discloses an instrument for taking cell samples, having a scraper with parallel through-slits opening in the end edge of the scraper.
According to the invention, the problem to catch by a simple spatula, without aspirator, a sample of viscous character which then easily can be smeared or washed from the spatula, is solved by the spatula of the kind referred to above having obtained the characterizing features of claim 1. By means of the apertures thus provided in the scraper the scraped off sample will be retained on the spatula by capillary action in the apertures, conditioned by the surface tension of the sample, without preventing the cellular sample from being released from the spatula when the sample is being smeared onto a slide or washed off in a transport solution.